Search for dark matter and compressed mass-spectra supersymmetry with the vector boson fusion topology in proton-proton collisions at $\sqrt{s}$ = 8TeV

Abstract

The first search for dark matter candidate production through pure electroweak vector boson fusion processes is presented. Events with two jets in the vector boson fusion topology and large missing transverse momentum are analyzed using data from proton-proton collisions at $\sqrt{s}$ = 8TeV collected with the CMS detector. In the context of supersymmetric models with a compressed mass spectrum, which may yield leptons and jets with momenta too low to detect efficiently, the two jets associated with the vector boson fusion topology boost the momentum imbalance from the escaping lightest supersymmetric particle (a dark matter candidate), providing a distinct signature which discriminates signal events from backgrounds. The dijet mass spectrum measured in data is observed to be compatible with the standard model expectations. Limits are set on the production cross section and mass of fermionic dark matter particles in the context of an effective field theory with a heavy mediator, as well as pairs of scalar bottom quarks that are nearly mass degenerate with the lightest supersymmetric particle.

Plots, figures, and diagrams from SUS-14-019

Figure File Caption
PNG, PDF The $m_{jj}$ distribution after all signal region selections, where the shaded band in the ratio plot includes the systematic and statistical uncertainties in the background prediction.
PNG, PDF (upper) Upper limit at the 95% CL on the cross-section as a function of mass M = $m_{\chi}$ = $m_{\tilde{b}}$. (lower) The 95% CL on the contact interaction scale, $\Lambda$, as a function of the DM mass $m_{\chi}$ for the scalar effective field theory DM model (upper). The validity of the effective field theory is quantified by $R_{\Lambda}$ = 80% contours, corresponding to different values of the effective coupling $g_{\text{eff}}$.

Table File Caption
PNG Predicted and observed rates for the control regions and signal region. The yields are used to calculate correction factors for the central selections and VBF selection efficiencies. Statistical uncertainties are cited for both the predicted and observed yields.
PNG Predicted rates after various stages of the cut flow for backgrounds and $\tilde{b}\tilde{b}jj$ signal events with $m_{\tilde{b}}$ = 300 CMS.GeV

-- ShoMaruyama - 2015-08-11

Topic attachments
I Attachment History Action Size Date Who Comment
png 2015-08-22_162900-SR-cutflow-table.png r1 manage 166.5 K 2015-08-22 - 23:47 AndresDelannoy
pdf GoldenPRLPlot.pdf r5 r4 r3 r2 r1 manage 22.2 K 2015-08-22 - 02:17 AlfredoGurrola
png GoldenPRLPlot.png r5 r4 r3 r2 r1 manage 28.8 K 2015-08-22 - 02:17 AlfredoGurrola
pdf MJJ-data-driven-unblinded-SR.pdf r3 r2 r1 manage 18.7 K 2015-08-22 - 08:26 AlfredoGurrola
png MJJ-data-driven-unblinded-SR.png r3 r2 r1 manage 19.2 K 2015-08-22 - 08:26 AlfredoGurrola
png sus14019_signal_cutflow.png r3 r2 r1 manage 166.5 K 2015-08-23 - 00:35 AndresDelannoy
png table.png r4 r3 r2 r1 manage 103.1 K 2015-08-25 - 11:29 AndresDelannoy
Topic revision: r14 - 2015-08-25 - FilipMoortgat

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